I haven´t ordered my jewlery model j
yet, because there are some questions before...

1st of all: is it possible for a jeweler here in town to insert gemstones into the steel model?
2nd: is it possible to make the steel model black? (with lineoil and heat)? (sure before inserting the gemstones)...

For a jeweler to insert stones you will need to make recesses in your design that except the stones. Also too, stones are usually held in place by metal prongs that bend over and secure the stones.

I don't know what lineoil is. Can you be more specific? There are numerous patinas that can be experimented with to alter the color, see Caswell Plating for starters. Keep in mind though that it is not 100% stainless steel, but rather a mixture of stainless steel and bronze. So when doing any kind of chemical reactions you need to realize that you'll be working with two completely different alloys bound together as one.

There are numerous reasons why you would get a Sketchup rejection. Can you send us the file? Or is it something you want to keep private. If don't mind people having it for personal use then upload it here as an attachment and someone from the forum will take a look at it and show you what's wrong.

There are moulds for the cabochon-cutted gemstones at the front of the fotoframe part and a little under...

"lineoil" is some natural oil that you can use to make steel black. you put it on an heat it up to 400°C. While burning anway it makes some chemical reaction with the metal (usualy used to protect iron not to get rusty) - lineoil is also a typical indrigent for oilcolour. That´s the german Name for it - maybee it´s called different in english...

1st of all: is it possible for a jeweler here in town to insert gemstones into the steel model?
2nd: is it possible to make the steel model black? (with lineoil and heat)? (sure before inserting the gemstones)...

1/ Possible but it is difficult and it will be hard to fins anyone with experience of having done it.

I wasn't able to download it from the Trimble Warehouse and I don't see a link to your DAE file. I was however able to see the 3D view on Trimble. From this view I can tell you that you may have a problem with thin walls. What are the basic dimensions of this item? Also, you'll want to make sure you have proper clearance on that hinge if you want to 3D print it in situ. If you don't have proper clearance it will be welded together.

As for lineoil I can't find any information about it other than it is an oil known about in Europe. That's ok though because I know what process you are talking about. Yeah, as Bill stated it's going to wear off eventually, but only from the high spots so that may look good depending on the starting color of the stainless steel / bronze.

The steel/bronze may be hard to bend over the edges of the stones so you may need to use epoxy or if you're going to use star sapphire as stated in the Trimble Warehouse description you can probably solder the stones in place being that star sapphire can withstand extremely high temperatures. The blackened base with blue star sapphire will look great!